Token-authenticated requests to Agent Bots, Labels, and affected Captain
endpoints return normal responses again. The regression was caused by
duplicate `current_account` callbacks in subclasses moving account
resolution behind the API entitlement check, leaving `Current.account`
unset.
## Closes
- https://linear.app/chatwoot/issue/CW-7641/5xx-errors-in-agent-bot-apis
## How to reproduce
1. Send `GET /api/v1/accounts/:account_id/agent_bots` with a valid
administrator API access token.
2. Observe a `500` from `validate_token_api_access` because
`Current.account` is `nil`.
3. With this change, account resolution runs in the base-controller
order and the request succeeds.
## What changed
- Removed redundant `current_account` callbacks from account-scoped
controllers that already inherit the callback from
`Api::V1::Accounts::BaseController`.
- Kept the standalone direct-upload controller callback unchanged.
- Added regression coverage for administrator API-token access to Agent
Bots.
